<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
<    <style>
    .box{
        margin: 50px auto;
        width: 200px;
        height: 100px;
        background: linear-gradient(to right, #fb3 50%,#58a 0) ;
        background-size: 30px 100%;
       
    }
</style>
</head>
<body>
<div class="box">

</div>
</body>
</html>